Terry Pratchett has invented a phantasmagorical universe in which a blissfully naive interplanetary tourist called Two-flower joins up with a drop-out wizard whose spells only seem to work half of the time.

Together they undertake a chaotic voyage through a crazy world filled with monsters and dragons, heroes and knaves. Pratchett has taken the sword and sorcery fantasy tradition and turned it in its ear to create an entertaining and bizarre spoof.

From Wikipedia: Heart of Darkness is a novella written by Joseph Conrad. Before its 1902 publication, it appeared as a three-part series (1899) in Blackwood's Magazine. It is widely regarded as a significant work of English literature and part of the Western canon.

The story details an incident when Marlow, an Englishman, took a foreign assignment from a Belgian trading company as a ferry-boat captain in Africa. Although Conrad does not specify the name of the river, at this time Congo Free State, the location of the large and important Congo River, was a private colony of Belgium's King Leopold II. Marlow is employed to transport ivory downriver; however, his more pressing assignment is to return Kurtz, another ivory trader, to civilization in a cover up. Kurtz has a reputation throughout the region.

This very symbolic story is actually a story within a story, or frame narrative. It follows Marlow as he recounts, from dusk through to late night, to a group of men aboard a ship anchored in the Thames Estuary, his Congolese adventure. The passage of time, and the darkening sky, during the fictive narrative parallels the atmosphere of the story. It should be noted from a structuralist point of view that Marlow is also the name of a town situated on the Thames further upstream from London.